Plastic ophthalmic lenses are classified by their refractive index, and the refractive index defines the power of the lens.
Hitherto, lenses having a low refractive index (1.52) was normally made by the thermal polymerization of diethylene glycol bis allyl carbonate. The process consisted in subjecting diethylene glycol bis allyl carbonate to the step of thermal polymerization in the presence of thermal initiator normally comprising diiso propyl peroxydicarbonate. Such a thermal polymerization consisted of a thermal cycle at different temperatures.
A disadvantage associated with such a known process is that of high power consumption and time consuming.